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How to do hovering pitch/throttle trim ?

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leloup
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11 Sep 2012 15:48 #1526 by leloup

How to do hovering pitch/throttle trim ? was created by leloup

All is in the tittle, i don't find how to do.

FDR
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11 Sep 2012 18:34 #1535 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

Well, you've got me!

While it is possible to use the trim values in mixing, I'm not sure what is it good for....

leloup
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11 Sep 2012 21:17 - 11 Sep 2012 21:18 #1548 by leloup

Replied by leloup on topic How to do hovering pitch/throttle trim ?

i have try to do it with a virtual chanel with a complex mixer to do a trim controled calculation and the TX is turned off to restart ... ?!?

Last edit: 11 Sep 2012 21:18 by leloup.

FDR
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12 Sep 2012 04:12 #1549 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

Really?
Please send the model ini file.

SadSack
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12 Sep 2012 05:09 - 12 Sep 2012 05:11 #1550 by SadSack

Replied by SadSack on topic How to do hovering pitch/throttle trim ?

Being able too trim hover pitch/throttle fly is really sweet feature helps keep sticks at mid point.
My tx i have 2 small rotatory pots on the front + 2 extra normal trim levers Which i can adjust hover in normal mode. Why? well if flying trex 600 nitro on a windy day i get more lift so lower hover point and no wind higher it. On my beam same apply's but if use 1800 and 2200 lipo's the weights different so hover point moves up or down on the stick. Other effect is going from idleup to normal mode you can have a big jump. Ok i've haven't got my curves set quite right but minor tweaks will always be needed. Joys of high end TX

helps you out with sloppy setup. There's a lot more to it but should give you the idea behind it.

Last edit: 12 Sep 2012 05:11 by SadSack.

FDR
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12 Sep 2012 05:25 - 12 Sep 2012 05:27 #1552 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

What I do not understand is that the throttle/pitch stick doesn't auto center, so you don't have an exact position to which trim to hover.
Furthermore if you do 3D, that would give a very assymetrical pitch behaviour.

Or are they just to trim the other function of the stick, i.e. the pitch trim applies in normal mode, while you are controlling the throttle with the stick, and the throttle trim needed in idle up modes, when you control the pitch?

EDIT: sorry, but I only have a submicro CP, which won't stay in place without continious stick movements, so I don't have the idea how it could help...

Last edit: 12 Sep 2012 05:27 by FDR.

leloup
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12 Sep 2012 09:36 - 12 Sep 2012 09:36 #1557 by leloup

Replied by leloup on topic How to do hovering pitch/throttle trim ?

The solution is to make a lock/unlock button on each point of a mix curve. With this you are doing an inverted 1-to-1 3 points curve (in sum to the throttle mix)with only the center point unlocked. The source will be a virtual channel with the left or right trim to command. Therefore only the center point of the curve will move with the trim.

For me is usefull according to the payload of my FPV multicopter.
(Sorry for my bad english, i hope so you understand).

Last edit: 12 Sep 2012 09:36 by leloup.

FDR
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12 Sep 2012 12:51 - 12 Sep 2012 18:39 #1560 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

I think I understand now, and may have a solution for it:

- On the trim list assign the TRIM_L- and TRIM_L+ to a virtual channel, say Virt1, and make the step a bit larger to see it's effect more easier.

- Define the throttle channel (ch3) as a three page complex mixer like that:
page 1: (mux=replace,) src=Virt1, curve=1-to-1, trim=on
page 2: mux=mult, src=THR, curve=3 point (0, 100, 0)
page 3: mux=add, src=THR, curve=1-to-1

Geez, that was hard!

Furthermore it still doesn't contain the normal trim, the flight modes, dual rates, or anything, it just demonstrates the hovering throttle...

Last edit: 12 Sep 2012 18:39 by FDR. Reason: typo

leloup
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13 Sep 2012 08:30 - 13 Sep 2012 08:31 #1574 by leloup

Replied by leloup on topic How to do hovering pitch/throttle trim ?

This is not working if you try to add with a normal heli mix(fmode ). My tx is was freezed with This. You must add more errors management in your code to don t result in impossible values.
A solution ro do This hov. trim is to create a special 3 points curve with invariablee first and third points. And the second point will be move by a selected unused trim. This special curve will be add to the throttle mix.
I don t know if i am clear with my bad English.

Last edit: 13 Sep 2012 08:31 by leloup.

FDR
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13 Sep 2012 08:43 #1576 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

Well, I don't see any reason why it shouldn't work with added fmode support, it just will be more complex. Don't forget, that the page order is crucial!
If you give me some time, I'll do it for you...

FDR
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13 Sep 2012 09:27 #1578 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

Could you post the original version of your model file without the hovering trims?

leloup
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13 Sep 2012 09:58 #1579 by leloup

Replied by leloup on topic How to do hovering pitch/throttle trim ?

It s the 6ch heli template without modification.

FDR
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13 Sep 2012 10:01 - 13 Sep 2012 10:02 #1580 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

I see.
Do you really need CCPM mixing? (EDIT: I mean what swash type do you use with the original fw?)
What heli we are talking about?

Last edit: 13 Sep 2012 10:02 by FDR.

FDR
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13 Sep 2012 12:18 - 13 Sep 2012 13:05 #1583 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

Well, I've almost got it, at least the throttle one.
There is indeed a bug, which cause a crash at the 6th mixer page.
However it can be done on 5 page, I just needed another for the throttle hold, but that can be implemented otherwise...

So the solution for the throttle channel is:
page 1: (mux=replace,) src=Virt1, curve=1-to-1, trim=on
page 2: mux=mult, src=THR, curve=3 point (0, 100, 0)
page 3: switch=FMODE0, mux=add, src=THR, curve=1-to-1
page 4: switch=FMODE1, mux=add, src=THR, curve=3 point (f.e.: 100, 75, 100)
page 5: switch=FMODE2, mux=replace, src=THR, curve=3 point (t.e.: 100, 100, 100) (or it could be defined as fixed)

For the throttle hold page 6 should be:
page 6: switch=RUD DR, mux=replace, src=THR, curve=fixed, scale=-100
...but it can be done simpler on the channel page:
safety=RUD DR, safe val=-100

...to be continued with the pitch channel...

Last edit: 13 Sep 2012 13:05 by FDR.

magic_marty
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13 Sep 2012 16:43 #1585 by magic_marty

Replied by magic_marty on topic How to do hovering pitch/throttle trim ?

on the pitch what i did was on the trim page set the R- and R+ to input of ch6 and it works...(not sure if that is what you all are trying to do) but it doesn't seem to affect anything other then the pitch and is much more simple then using the mix page...i noticed on the throttle trim when used it not only moves the throttle it also moves the pitch as well...

FDR
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13 Sep 2012 17:02 #1586 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

Yes, it is trivial, but we are trying to make such trim method, which only effects the mid-range of the stick...

leloup
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13 Sep 2012 19:33 #1588 by leloup

Replied by leloup on topic How to do hovering pitch/throttle trim ?

Yesss !

very nice. Indeed the order is very important (an do not use the page 6 !)

FDR
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13 Sep 2012 19:52 - 14 Sep 2012 08:15 #1589 by FDR

Replied by FDR on topic How to do hovering pitch/throttle trim ?

PB has already corrected the issue, so in the next release you can use up to 10 mixers per channel.

BTW I've made the pitch channel too at work, but I forgot to post it.
But it is basicly the same, just uses Virt2 and different curves on the Ch6...

Last edit: 14 Sep 2012 08:15 by FDR. Reason: typo